Driving gear for boats



June 2, 1925.

F. R. DRAVQ DRIVING GEAR FOR BOATS Filed March 21, 1925 3'Sheets-Sheet 1 June 2, 1925. I 1,540,259

F. R. DRAVO DRIVING GEAR FOR BOATS H Filed March 21, 1925 '5 Sheets- Sheet 2 lllllllllllllllllllllll/Illlllllllllllll f9 .l v IIHIIIIIIIll-IlllllllllllllllIIlllllllllllllllllllllll June 2, 1925.

F. R. DRAVO DRIVING GEAR FOR BOATS FiledMarph 21, 1925 3 Sheets-Sheet 5 INVENTOR %TM% W M -QM me mad Patented June 2, 1925.

UNITED STATES FRANK R. DRAVO, 0F SEWIGKLEY, PENNSYLVANIA, ASSIGNOR TO THE DRAVO GON- TRAC'IING COMPANY, OF IIT'ISBURGH, PENNSYLVANIA, CORPORATION OF PENNSYLVANIA.

DRIVING GEAR FOR BOATS.

Application filed March 21, 1925. Serial No. 17,222.

To all whom it may concern:

Be it known that I, FRANK R. DRAVO, a citizen of the United States, residing at Sewickley, county of Allegheny, and State of Pennsylvania, have invented a new and useful Improvement in Driving Gears for Boats, of which the following is a full, clear, and exact description.

. The present invention relates to means for transmitting the drive from a power unit to the paddle wheel shaft of a boat having the paddle wheel located at the stern.

It is customary at the present time in tow boat construction to locate a paddle wheel at the stern of the boat and drive the same by means of a power unit, such as a motor, located at a convenient point in the boat. The drive is transmitted from the motor to the paddle wheel shaft through driving connections comprising a cross shaft and means located at the sides of the boat and operatively connecting the corresponding ends of the paddle wheel shaft and cross shaft, which means may either be gearing or sprocket chains engaging driving sprockets 011 the ends of the shafts. lVith either form of drive, it has heretofore been practically impossible to transmit the drive equally to both ends of the paddle wheel shaft, that is,

to apply equal amounts of driving torque thereto. In the case of the sprocket chain drive, there is apt to be a slight difference in the length of the chains when new and the chains and sprockets will wear unevenly and one chain will have a tendency to stretch more than the other in use, or the bearings may wear unevenly. The result is that in time one chain and its sprockets will be doing practically all the work of driving the paddle wheel. This lowers the efiiciency of the driving connections between the motor and paddle wheel, and produces such unequal strains in the] driving connections as to cause frequent breakage of theoverloaded chain and sprockets. In the case of the gear drive, there is a large number of gear-teeth which aresubjected to constantwear, so that more play soon develops in the gear drive at one side of the boat than in that of the other side thereof, or the bearings may wear un-' evenly. The result is the same as in the sprocket chain drive, that is, the gearing at the opposite sides of the boat will soon be transmlttingthe drive from the motor to the paddle wheel shaft unequally.

By the present invention,"I overcome the above difliculty by forming thecross shaft in sections and driving the same through differential gearing. This form of drive permits a relative movement between the sections of the cross shaft to take up anyslack in'the driving connections at the opposite sides of the boat and enables such driving connections to apply equal amounts of driving torque to the opposite'ends of the paddle wheel shaft. I have also provided novel means for housing and lubricating the differential gearing and supporting the bear: lugs for the adjacent ends ofthe propeller shaft and cross shaft. I

In the accompanying drawings, I have illustrated my invention in connection with a boat having sprocket chain driving connections between the motor and paddle wheel shaft.

In the drawings 3+- Figure 1 is a plan view of a boat having invention applied thereto Figure 2 is a side elevation of the boat; Figure 3 is a'plan view of the paddle wheel'andthe driving connections between the same and the propeller shaft;

F igure i is a. detail sectional view of the on the sides of the boat. Fixedto the ends.

of the paddle wheel shaft are driving sprockets 6. Extending transversely of the boat and parallel to the paddle wheel shaft is a cross shaft 7 formed in two sections and having its outer end portions journaled in bearings 8. Fixed to the outer ends of the cross shaft are sprockets 9 and connecting the sprockets on the corresponding ends of the paddle wheel-shaft and cross shaft are sprocket chains 10.

Extending longitudinally of the boat is a propeller shaft 11 adapted to be driven by a motor 12 or other form of power unit. The propeller shaft is operatively connected to the cross shaft through differential gear- 'j'acent its lower. edge portion;

ing. The differential gearing is housed in a casing 1'3, shown in detail in Figures 5',

6 and T. The rear end portion of the propeller shaft. is journaled in a bearing let mounted on the casing and the inner-end portions of the sections of the cross shaft are joui-naled in bearings 15 also mounted on the casing. Fixed to, the end of the propeller shaft within the casii'i'g i's ai bevel pinion 16 which n eshes with a bevel rin gear 1"? carried by a gear disk 18, the hub portion 19 of which is jou'rnaled on the inner ,end portions of the sections of the cross shaft 7. The gear disk 18 carries two diametrically f opposite inionsao rotatablymounted on pins 21 of ending lnto openings in the hub 19.

These pins are held in position by the i gear 17 which is bolted to, the disk 18 The difierentinl pini'ons 2O nieshwith differentialf gears fixed to'th'e inner ends of the sections: of the cross shaft.

It will be apparent t' gearingbetween the prope ler shaft 11 and the cross shaft 7 provides" a positive driving connection between the propeller shaft and" the cross; shaft and, at the sa ne tini e enables the sections of the rossshaft" to have the necessary relative rotation forniaintaining equala noun'ls of tension nil; the two sprocket chains 10L it w ll. also be apparent. that if gear trains were substituted for the sprocket chains and. driving sprockets at the sides of the boat, the diffe ential gearing in the driving connection between the propoller shaft and cross shaft would enable the drive to be transmitted'equally through sueh gear trainsg, A f

In case one of the sprocket c hains'or some t the teeth of a driving sproeliet or, a cross- L t section should break, it: iouldbe deable to couple the geardisl 18 and] the bevel gears23' rigidly together so as to, revolve as a unit. To that end i'efei-ring to Figure 1, the hub 19 of the gear disk 18 has a hole 24 extending therethrough which is adapted to be aligned. with similar holes 25 in the bevel gears through these parts together. The gearing aligned holes to, Couple the out in said top plate. This: cover has anangle 81 secured to its outer siirface ad- This angle adaet'ed to engage the plate 28, whereby the cover is supported on the plate. The cover is provided with suitable recesses 32 differential bevel at" the differential A bolt may be passed edges of the recesses 32, these angles being shaped to lit the bearings; The cover may be IBZtClll removed from the casin b 7 sunply nfting lb out of engagement with the plate 28 and the bearings 1d and 15. The

end portion of the plate 28 which supports the bearinq'lt is additionally supported by and a bracket 35). I li'le l have illustrated' my invention in connection with a sprocliethchain drive between the cross shaft and paddle, wheel sljiafft, it willb'e" perfectly apparent that the invention isequally applicable to construetions in which there is a gear drive at each side of the'boat' between the cross shaft and paddle wheel shaft. v

1., In, a boat, a paddle wheel shaft, a power unit, and driv glconnjections between the eiids of saidshaft and said power unitii'iclu'ding differential gearing, substantially as described. a i

2. In a boat, apa'ddie wheel shaft ex",- tending transversely thereof, cross she. extending parallel to the paddle wheel shaft, drivingconnec ens at the sides of the boat bet een' tli'eeorresponding ends of said sh f5; a power unit'for driving said; cross shaft, and differential gearing 1n the driving fob ed in two section gdriving connections at the sides of theboat between the corresponding ends of said shafts, a propeller shaft, and d'ijfi'e'rential gear'ihg mounted on said prop'eller shaft: and on the fer ends of the secti'oi'isof the cross she t, substantially as described.

ft, In a boat, paddle Wheel shaft, a cross shaft formed in two sections, driving connections at thesides of the boat between the corresponding ends of said shafts, a pro.- pelle'r shaft, differential gearing mounted on said propeller shaft and on the inner ei 'ds" ofthe sections of the cross shaft, and me ns for coupling the. portion of said differential gearing inounted jon the cross shaft together torevolve as aunit, substantially asdescribed. a In a'boat, a paddle wheel shaft extending transversely thereof and having driving sprockets mounted on the ends thereof, a' cross shaftextending parallellto the paddle wheel shaft and having driving sprockets mounted on the ends. thereof, sprocket chains engaging the sprockets on the c01 ?v respondingends of said shafts, andj' neans shaft, and differential gearing connecting the propeller shafts with the cross shaft, substantially as described.

7. In a boat, a paddle wheel shaft extending transversely thereof and having driving sprockets mounted on the ends thereof, a cross shaft extending parallel to the paddle wheel shaft and formed in two sections, driving sprockets mounted on the outer ends of said sections, sprocket chains engaging the sprockets on the corresponding ends of the paddle wheel shaft and cross shaft, a propeller shaft, and differential gearing mounted on said propeller shaft and on the inner ends of said sections, substantially as described.

8. In a boat, a paddle wheel shaftextending transversely thereof and having driving sprockets mounted on the ends thereof, a cross shaft extending parallel to the paddle wheel shaft and formed in two sections, driving sprockets mounted on the outer ends of said sections, sprocket chains engaging the sprockets on the corresponding ends of the paddle wheel shaft and cross shaft, a propeller shaft, differential gearing mounted on said propeller shaft and on the inner ends of said sections, and a casing enclosing said differential gearing, substantially as described.

9. In a boat, a paddle wheel shaft extend-- ing transversely thereof and having driving sprockets mounted on the ends thereof, a cross shaft extending parallel to the paddle wheel shaft and formed in two sections, driving sprockets mounted on the outer ends of said sections, sprocket chains engaging the sprockets on the corresponding ends ofthe paddle wheel shaft and cross shaft, "a propeller shaft, differential gearing mounted on said propeller shaft and on the in ner ends of said sections, a casing enclosing said difierential gearing, and bearings for the propeller shaft and sections of thecross shaft mounted on said casing, substantially as described.

10. In a boat, a paddle wheel shaft extending transversely thereof and having driving sprockets mounted on the ends thereof, a cross shaft extending parallel to the paddle wheel shaft and formed in two sections, driving sprockets mounted on the outer ends of said sections, sprocket chains engaging the sprockets on the corresponding ends of the paddle wheel shaft and cross shaft, a propeller shaft, differential gearing I mounted on said propeller shaftand on the inner ends of said sections, a casing for said gearing having a top plate provided with an opening therein, a coverfor said casing, the lower end portion of which has a sliding fit with the edges of said opening, and means carried by said cover adjacent said lower endv portion for engaging'said top plate and limiting the downward movement of said cover, substantially as described.

'11. In a boat, a paddle Wheel shaft extending transversely thereof and having driving sprockets mounted on the ends thereof, a cross shaft extending parallel to the paddle wheel shaft and formed in two sections, driving sprockets mounted on the inner ends of said sections, a casing for said gearing having a top plate provided with an opening therein, bearings for the propeller shaft and the sections of the cross shaft mounted on said top plate, and a cover for said casing, the lower end, portion of which has a sliding fit with the edges of said opening, said cover having recesses in its faces to receive said bearings, substantially as described. v

In testimony whereof I have hereunto set my hand. f

- FRANK R. DRAVO. 

